Over the past decades, rapid development of mobile communications networks has brought more and more convenience to people's life.
The following describes a communication process in the prior art by using FIG. 1 as an example. When a correspondent node CN (Correspondent Node) communicates with a mobile node MN (Mobility Node) through a mobile communications network, a data packet is sent from the correspondent node, routed to a packet data network gateway PGW (Packet Data Network Gateway, that is, PDN Gateway) of the MN through a network (Internet), and transferred by the PGW to a serving gateway SGW (Serving Gateway) at a current location of the MN, and then the serving gateway SGW sends the data packet to the MN by using a base station. When the MN returns a data packet, the data packet must also pass through the SGW and the PGW, and be routed to the CN through the Internet. The PGW is a home packet data network gateway of the MN.
In this case, as shown in FIG. 1, all communication data of the MN needs to be forwarded by the PGW of the MN. Even though the MN and the CN are in close proximity and are within a coverage range of a same serving gateway SGW, communication between the two terminals still needs to be routed to the PGW of the MN, which leads to roundabout communication routing between the MN and the CN to some extent.
Further, deployment density of mobile gateways increasingly rises with development of mobile broadband networks. Meanwhile, the scope of people's life is continuously extended, and users often move to coverage ranges of mobile gateways of other non-home packet data network gateways in daily life. This exacerbates the problem of roundabout communication routing of a mobile node, and further causes a severe waste of transmission resources of a mobile communications system and higher end-to-end latency of the mobile node.